Last year we initiated a program on the molecular biology of cornea. The major finding was that many of the abundant proteins of the corneal anterior epithelial cells of the mouse, human, kangaroo, chicken, and squid are either related or identical to metabolic enzymes, as are the lens crystallins. Indeed, many of these abundant corneal proteins are the same as those used as lens crystallins. Moreover, as with the lens crystallins, a taxon specificity was observed. In addition, we cloned the cDNA and gene for the most abundant protein in the epithelial cells of the mammalian cornea, class 3 aldehyde dehydrogenase (ALDH). This year we made transgenic mice that carry the 5' flanking sequence of the class 3 ALDH gene fused to a reporter gene to test whether this promoter preferentially directs gene expression in the cornea. Ten founder mice have been bred. Five ALDH and two 60 kD protein cDNAs have been cloned from the mouse cornea. The 60 kD protein is an abundant corneal protein that is highly conserved between mouse and human. A chicken corneal cDNA library also has been made in order to clone cyclophilin, an enzyme that last year was shown to comprise approximately 10% of the protein of the epithelial cells of the chicken cornea. Interestingly, this enzyme does not seem especially abundant in the mammalian cornea.